TWI381252B - A focal length adjustment method for an exposure apparatus of a belt-like workpiece and an exposure apparatus for a belt-like workpiece - Google Patents

Description

Exposure device for strip workpiece and focal length adjustment method in exposure device for strip workpiece

The present invention relates to an exposure apparatus for patterning an elongated strip-shaped workpiece of TAB (Tape Automated Bonding) or FPC (Flexible Printed Circuit) and a method of adjusting a focal length in the exposure apparatus.

In a display panel such as a liquid crystal panel, a mobile phone, a digital camera, an IC card, or the like, a thin film circuit board in which an integrated circuit is mounted on a resin film such as polyester or polyimide of a thickness of about 25 μm to 125 μm is used. In the manufacturing step of the thin film circuit board, for example, a strip-shaped workpiece having a width of 160 mm, a thickness of 100 μm, and a length of several hundred m is generally wound around a reel.

Further, the thin film circuit board is formed by adhering a conductor (for example, a copper foil) to the resin film. The production of the thin film circuit substrate is carried out by repeating the steps of applying the resist, the step of exposing the desired circuit pattern, the developing step of the resist, and the etching step of removing the unnecessary conductor, for example, four to five times. In each step, the thin film circuit substrate is taken up by a reel, processed, and wound again on a reel. Hereinafter, the thin film circuit substrate will be referred to as a strip-shaped workpiece.

An exposure apparatus that transfers a circuit pattern to each exposure region while conveying the above-described strip-shaped workpiece is disclosed, for example, in Patent Document 1.

Fig. 5 shows an example of the configuration of an exposure apparatus for a belt-shaped workpiece.

The strip-shaped workpiece W (hereinafter also referred to simply as the workpiece W) is superposed on a spacer for protecting the workpiece W and wound in a roll shape on the take-up drum 1. When pulled out by the take-up drum 1, the spacer is wound around the spacer winding drum 1a.

The strip-shaped workpiece W wound up by the take-up drum 1 is held by the encoder roller R3 and the pressing roller R3' via the loose portion A1 and the intermediate guide roller R2. The encoder roller R3 is for confirming whether or not a roller has slipped in a conveyance roller to be described later when the workpiece is conveyed.

The strip-shaped workpiece W pulled out by the take-up reel 1 is passed through the exposure unit 3, and is held by the transfer roller R4 and the pressing roller R4'. The workpiece W is conveyed to the workpiece stage 10 of the exposure unit 3 by being conveyed by a predetermined amount set by the rotation of the conveyance roller R4.

The exposure unit 3 is provided with a light irradiation unit 4 composed of a lamp 4a and a condensing mirror 4b, a mask M having a pattern (mask pattern) exposed to the workpiece, and a projection lens 5. Further, the workpiece stage 10 is attached to the workpiece stage drive mechanism 6, and can be driven up and down, in the left and right direction, and can be rotated about the axis perpendicular to the workpiece stage surface.

In the exposure unit 3, the back side of the exposed region of the strip-shaped workpiece W is held on the surface of the workpiece stage 10 by means of holding means such as vacuum suction. This is to prevent the area where the workpiece W is exposed from being fixed at the imaging position of the mask pattern projected by the projection lens 5, so as to prevent the workpiece W from moving in the optical axis direction or the transport direction during exposure.

Fig. 6 is a perspective view showing a portion of the mask, the projection lens, and the workpiece stage of the exposure apparatus of Fig. 5 taken out.

As shown in the figure, two masks (mask marks) MAM are formed in the mask M, and the workpiece W is pressed for each exposure area. The number of the cover marks MAM corresponds to an alignment mark (work mark) WAM in which two parts are formed. In the present example, the workpiece mark WAM is formed in the through hole of the peripheral portion of the strip-shaped workpiece W. However, when the strip-shaped workpiece W has light transparency, the mark WAM may be formed on the workpiece W.

Further, the workpiece stage 10 is formed with a notch 10a or a through hole at a position (two locations) where the mask mark MAM is projected by the projection lens 5, and an alignment microscope (2 sets) is disposed under the workpiece stage 10 ) 12.

The alignment microscope 12 passes through the notch 10a or the through hole of the workpiece stage 10 to detect the mask mark MAM and the workpiece mark WAM.

When the workpiece mark WAM is conveyed onto the notch 10a of the workpiece stage 10, that is, above the alignment microscope 12, it is adsorbed and held on the workpiece stage 10.

The alignment light illumination means 11 is inserted above the mask M by a moving mechanism (not shown). The alignment light is irradiated to the mask mark MAM by the alignment light illumination means 11, and the mask mark image is projected onto the alignment microscope 12 by the through hole as the workpiece mark WAM by the projection lens 5.

The alignment microscope 12 is used to detect the projected mask mark image. At the same time, an image of the edge of the through hole as the workpiece mark WAM is also detected.

The control unit 20 shown in Fig. 5 performs image processing by inputting an edge image of the mask mark MAM image and the workpiece mark WAM detected by the alignment microscope 12. Then, the workpiece stage driving mechanism 6 is driven in accordance with the position information of the mask mark MAM and the workpiece mark WAM so that the two are formed in a predetermined positional relationship, and the mask M having the mask pattern such as a circuit is formed. The exposure area of the workpiece W is opposite.

After the alignment is completed, the exposure light emitted by the light irradiation unit 4 is transmitted through the mask M and the projection lens 5 to the workpiece W, and the mask pattern is transferred to the workpiece W.

When the exposure is completed, the strip-shaped workpiece W is nipped by the transport roller R4 and the pressing roller R4', and is transported and exposed so that the next exposure region comes onto the workpiece stage 10.

As described above, the strip-shaped workpiece W is sequentially exposed, and is wound around the winding drum 2 via the guide roller R5 and the loose portion A2. At this time, the spacer is taken out by the spacer unwinding roller 2a, and the exposed strip-shaped workpiece W is wound around the winding drum 2 together with the spacer.

The surface position of the workpiece stage 10 is adjusted to the focus position of the projection lens 5 by the workpiece stage driving mechanism 6 in advance.

(Patent Document 1) Japanese Patent No. 2886675

The circuit pattern formed on the thin film circuit board is gradually increased in density and miniaturization as the electronic device is speeded up, multi-functionalized, and miniaturized, and the exposure accuracy of the exposure apparatus is required to increase year by year. Therefore, the projection lens of the exposure device must be a higher resolution. However, when a high-resolution projection lens is placed on the exposure apparatus, it is necessary to perform focus adjustment that is not required in the past.

The reason is explained below. Here, the focal length adjustment refers to focusing a mask pattern image projected on a workpiece.

(1) The focal length position of the projection lens is changed for the designed position due to the expansion and contraction of the lens caused by the temperature change or the change in the refractive index of the air between the lens and the lens caused by the change in the air pressure.

The change in the focal position is not a problem if it is within the depth of the projection lens (Depth of Focus). However, when the change in the focal length position is greater than the depth of focus, the exposure accuracy is lowered.

(2) In general, the projection lens has a tendency to reduce the depth of focus when the resolution is improved. For example, in a projection lens having a resolution of about 6 μm, the depth of focus is about 50 μm, and when the resolution is about 4 μm, the depth of focus is about 30 μm.

(3) In addition, as the projection lens is increased in resolution, the number of lenses used is increased, and the space between the lens and the lens is increased in the lens barrel supporting the lens. The pressure in the space is difficult to follow the change in the air pressure in the environment in which the lens is placed. When the air pressure is low, the force applied by the lens barrel toward the outside is applied to the lens system. Further, when the air pressure becomes high, the opposite direction acts toward the lens barrel. The force of the inside press. Therefore, the high-resolution projection lens system is susceptible to fluctuations in the air pressure, and the change in the focal length position also becomes large.

(4) In the past, when the exposure apparatus was installed in the user's factory, the distance from the mask to the workpiece (also referred to as the distance between the original paintings) was adjusted in such a manner that the projection image of the mask pattern was imaged on the workpiece. If the temperature of the room in which the device is installed is managed to be substantially constant, the change in the focal position can be within the depth of focus of the projection lens. That is, if the adjustment of the distance between the original paintings is performed at the time of installation of the apparatus, it is not necessary to perform again thereafter.

However, when the projection lens mounted on the exposure device is of high resolution The change in the focal position due to changes in temperature or air pressure will be greater than the depth of focus of the projection lens.

As described above, the cause of the change in the focal position is caused by the change in temperature and the change in the air pressure, and in particular, the person who causes a large influence is the temperature change caused by the operation of the device.

There are three main temperature changes caused by the operation of the device.

(a) When the exposure light passes through the projection lens, the lens absorbs the light energy to raise the temperature. On the other hand, the shutter is closed by replacement of the workpiece or the like, and when the light does not pass through the lens, the temperature of the lens is lowered. Based on this temperature change, the lens is expanded and contracted, and the focal position is changed.

(b) As the temperature of the lens changes, the lens barrel for holding the lens also expands and contracts by changing the temperature by heat conduction. Thereby, the position of the lens is changed, and the position of the focal length changes.

(c) The temperature change of the lens barrel or the heat of the light source unit that emits the exposure light is transmitted to the casing of the apparatus, and the entire apparatus is expanded and contracted. Thereby, the distance from the mask stage to the workpiece stage changes, and the focal length position changes.

Therefore, in order to maintain the desired exposure accuracy, it is necessary to periodically confirm the focal length position every predetermined time or number of exposures in one day, and to mask the projection image of the mask on the workpiece. Adjustment of the position of the workpiece (like the distance between the original paintings) (focal length adjustment).

The most simple method of performing the focus adjustment is to expose the focal length adjustment pattern to the workpiece by actually changing the distance between the original paintings, and to set the image-to-picture distance at the position where the pattern is optimally formed by the development result. but This method has the following problems.

Since it is necessary to repeatedly perform exposure and development, it takes time to adjust the settings, and it is not practical to perform several times in one day.

Consider the case where the focus adjustment is performed by the above method and the middle of the exposure process (in the middle of a batch). When the workpiece is a sheet, when a certain workpiece finishes the exposure processing and is carried out by the device, the next workpiece is temporarily stopped. Next, the mask and the workpiece are replaced with a focus adjustment user to perform focus adjustment.

However, when the workpiece is in the form of a strip, it is difficult to replace the mask and the workpiece because there is no interruption in the middle of the workpiece. Therefore, it is impossible to perform focus adjustment in the middle of the exposure process (in the middle of a batch).

Further, in the method of adjusting the focal length without performing exposure and development, it is conceivable to project the mask pattern through the projection lens, and to detect the projected pattern image so as to adjust the distance between the original image and the image.

However, the following problems also occur in this method.

When the projection image is used for the focus adjustment, a focal length adjustment pattern is formed at a certain portion of the mask. Further, it is necessary to provide an illumination means for illuminating the focus adjustment pattern and an image receiving means for detecting and accepting the projected pattern image. However, setting the illumination means or the receiving means for the focus adjustment causes the device cost to rise.

Therefore, it is also considered to use the mask mark formed for the alignment to perform the focus adjustment (the mask alignment mark is also used as the focus adjustment pattern). The mask mark is projected onto the alignment microscope by aligning the illumination system, so if the mask mark can be used for focus adjustment, there is no need to reset Lighting means or subject means.

However, as shown in the following description, this method also has problems.

The alignment accuracy required in the exposure apparatus of the current strip-shaped workpiece is about ±5 μm, and the size of the mask mark for achieving the accuracy is, for example, a circle having a diameter of about 0.5 mm (the diameter of the through-hole as the workpiece mark is about 1mm).

On the other hand, when it is desired to perform, for example, the focal length adjustment of the projection lens having a resolution of 4 μm, it is confirmed whether or not the same pattern image is seen to be in focus or not. Therefore, the pattern for focal length adjustment must be a pattern of lines and spaces (L&S, line and space) of several μm (for example, 6 μm). Therefore, the mask mark is too large and cannot be used for focus adjustment.

Further, a lens for imaging the projection image on the image receiving surface thereof is provided on the alignment microscope. Therefore, the alignment microscope also changes in the focal length position in accordance with the change in temperature or air pressure, similarly to the projection lens. Therefore, when the alignment microscope receives the image of the focus adjustment pattern and performs the focus adjustment, it is necessary to correct the change in the focal length position of the alignment microscope, but this method has not been established yet.

The present invention is directed to solving the problems of the above-mentioned prior art, and the object of the present invention is to perform focus adjustment in the middle of exposure processing (half of a batch) in an exposure apparatus for a belt-shaped workpiece even in a strip shape. In addition, it is not necessary to add a dedicated illumination means or a receiving means for the focus adjustment, and the installation cost is not increased, and the focus adjustment can be performed in a short time.

In order to solve the above problems, in the present invention, in the above workpiece stage A light transmitting member is disposed in the through hole or the notch, a focal length adjusting pattern for the alignment microscope is formed in the light transmitting member, and a focal length adjusting pattern for the projection lens is formed in the mask, and the focal length of the projection lens is detected by the alignment microscope. The focus pattern is adjusted by adjusting the pattern and the focus adjustment pattern for the alignment microscope described above.

That is, the focus adjustment is performed as shown below.

(1) comprising: a light irradiation portion that irradiates the exposure light; a mask stage that supports the mask in which the pattern and the mask alignment mark are formed; and an elongated tape-shaped workpiece on which the workpiece alignment mark is formed, and a workpiece stage having a notch or a through hole; a projection lens that projects the pattern formed on the mask on the workpiece; a light transmission member disposed on the through hole or the notch of the workpiece stage; and the light transmission member An alignment microscope below; and an exposure apparatus for detecting a strip-shaped workpiece of the control portion of the mask by detecting the mask alignment mark and the workpiece alignment mark by the alignment microscope, wherein The mask forms a focal length adjustment pattern for the projection lens, and the light transmission member forms a focus adjustment pattern for the alignment microscope, and the control unit detects the focal length adjustment pattern of the projection lens and the alignment by the alignment microscope. The microscope adjusts the pattern with a focal length to adjust the focus.

(2) In the above (1), the alignment microscope includes: a first image receiving unit that detects an image at a low magnification; and a second image receiving unit that receives an image at a high magnification, and when the mask is aligned with the workpiece, The first image receiving unit detects the alignment mark, and when performing the focus adjustment, the second image receiving unit detects the focus adjustment pattern.

(3) In the above (1) and (2), the mask alignment mark formed on the mask is in a ring shape, and the projection lens focal length adjustment pattern formed on the mask is formed as the mask pair. A pattern of lines and spaces inside the wheel of the quasi-marker.

(4) In the above (1), (2), and (3), the workpiece alignment mark is used as a through hole formed in the strip-shaped workpiece.

(5) The method of adjusting a focal length in the exposure apparatus of the strip-shaped workpiece according to the above (1) to (4), characterized in that the image of the focus adjustment pattern for the alignment microscope is received by the alignment microscope, a first step of moving the workpiece stage in the optical axis direction (Z direction) so that the pattern is focused; receiving the image of the projection lens focal length adjustment pattern, so that the pattern is focused, and the mask stage is oriented a second step of moving in the optical axis direction (Z direction); and in a state where the distance from the mask stage to the workpiece stage is maintained at the end of the above step, the workpiece stage and the mask are carried with respect to the projection lens The third step of moving the mask stage and the workpiece stage in such a manner that the stage becomes an equal distance.

In the present invention, the following effects can be obtained. (1) Forming a focal length adjustment pattern in the mask, and detecting and imaging the projection image by the alignment microscope, and adjusting the distance between the original paintings by focusing, so that it is not necessary to expose and develop the pattern. Focus adjustment is performed in a short time.

(2) The pattern for adjusting the focal length formed in the mask will be formed in the mask Since the alignment mark is formed in a ring shape and formed on the inner side thereof, the focus adjustment can be performed in the middle of the exposure process (in the middle of a batch) even in the case of a strip-shaped workpiece which is not interrupted in the middle of the workpiece.

(3) Further, by performing alignment of the mask with the workpiece, the focus adjustment pattern can be aligned in the field of view of the alignment microscope. Therefore, if the alignment of the mask and the workpiece is performed, the focus adjustment operation can be immediately performed, and even if the focus adjustment is performed in the middle of a batch, the output can be prevented from being lowered as much as possible.

(4) Since the focal length adjustment pattern of the alignment microscope is provided on the workpiece stage, when the distance between the original paintings is adjusted, the change portion of the focal length position of the alignment microscope can be corrected.

The device configuration of the embodiment of the present invention is shown in Figs. 1 and 2 . 1 is a view showing an overall configuration of an exposure apparatus for a strip-shaped workpiece of the present embodiment, and FIG. 2 is a view showing an apparatus for displaying alignment light, a mask stage, a projection lens, and a workpiece in the apparatus shown in FIG. A diagram of the stage and the part of the microscope.

In the first and second figures, the mask stage 13 is moved by at least the Z direction (the optical axis direction, the vertical direction of the drawing) by the mask stage moving mechanism 14.

The workpiece stage 10 is also moved in the optical axis direction (Z direction, the vertical direction of the drawing) by the workpiece stage moving mechanism 6.

The mask stage 13 and the workpiece stage 10 are positions in which the focal length (design value) of the projection lens 5 is the Z direction (optical axis direction) of each stage. Move at the origin position. The control unit 20 is stored at the origin position and the movement origin of the Z direction (optical axis direction) of each of the stages 14 and 10.

The workpiece stage 10 is provided with a notch 10a or a through hole, and an alignment microscope 12 is disposed below the workpiece stage 10. Among them, the alignment microscope 12 is independently present with respect to the movement of the workpiece stage 10.

A notch or a through hole (hereinafter mainly described by a notch) 10a of the workpiece stage 10 is embedded with a glass plate 10b that is made of a material that exposes light of a wavelength. The glass plate 10b does not protrude above the surface of the workpiece stage 10.

The alignment microscope 12 is disposed below the glass plate 10b. As in the conventional example, the alignment microscope 12 is disposed at a position where the alignment mark MAM is formed in accordance with the number thereof. In the present embodiment, since the alignment mark MAM is formed at two locations, the alignment microscope 12 is also provided with two in place.

Further, the alignment microscope 12 is provided with two CCD cameras for receiving images for each unit. One of them is for low magnification and the other is for high magnification. The magnification is changed by switching the optical path. The low magnification (for example, 1.5 times) is used to detect the mask mark and the workpiece mark when the mask is aligned with the workpiece. On the other hand, a high magnification (for example, 10 times) is used for detecting a focus adjustment pattern in the focus adjustment.

The configuration other than the above is basically the same as that of Fig. 5, and the strip-shaped workpiece W wound by the unwinding drum 1 is sandwiched by the encoder roller R3 and the pressing roller R3' via the loose portion A1 and the intermediate guide roller R2. The conveyance roller 3 is conveyed by the conveyance roller R4 and the pressing roller R4'. . The workpiece W is conveyed to the workpiece stage 10 of the exposure unit 3 by a predetermined amount set by the rotation of the transport roller R4.

The exposure unit 3 is provided with a light irradiation unit 4 including a lamp 4a and a condensing mirror 4b, a mask M having a pattern (mask pattern) exposed to the workpiece, and a projection lens 5. Further, the workpiece stage 10 is attached to the workpiece stage driving mechanism 6, and can be driven up and down, in the left and right direction, and can be rotated about the axis perpendicular to the workpiece stage surface.

The strip-shaped workpiece W is exposed after the exposure portion 3 is aligned, and the exposed strip-shaped workpiece W is wound around the winding drum 2 via the guide roller R5 and the loose portion A2.

Here, the focal length adjustment pattern of the projection lens and the focal length adjustment pattern for the alignment microscope will be described.

As described above, the size of the mask mark (for example, 0.5 mm in diameter) is not the same as the size of the focus adjustment pattern (for example, L&S of 6 μm). The focal length adjustment pattern is formed inside the mask mark by the difference in the size.

That is, as shown in Fig. 3 (a) and (b), the mask mark MAM is formed into a ring (ring) shape having an outer shape of, for example, φ 0.5 mm and an inner diameter of φ 0.3 mm. Next, a focal length adjustment pattern (hereinafter, a focal length pattern FP) of L & S of, for example, 6 μm is formed inside the inner diameter of φ 0.3 mm. Therefore, when the alignment of the mask M and the workpiece W is performed, when the mask mark MAM is projected on the alignment microscope, the focal length pattern FP is simultaneously projected onto the alignment microscope 12. In the third diagram (a), the projection image of the mask mark MAM and the focal length pattern FP and the through hole (work mark) are enlarged. The edge of the WAM) and the focal length adjustment pattern AP of the alignment microscope formed on the glass plate, and Fig. 3(b) are enlarged views showing the mask marks and the focal length patterns FP and AP of (a).

The focal length adjustment pattern AP for the alignment microscope is formed on the glass plate 10b that is fitted into the notch or through hole of the workpiece stage 10.

The position at which the pattern AP is formed is formed at a position where the mask mark MAM or the focal length pattern FP is not overlapped, and is formed in the field of view of the alignment microscope 12. For example, as shown in Fig. 3(b), the inner side of the annular mask mark image is next to the focal length pattern FP image.

Next, the alignment of the mask M and the workpiece W and the order of the focal length adjustment of the projection lens and the alignment microscope will be described.

(1) The workpiece W is transported by a predetermined distance by the rotation of the transport roller R4, and the through hole as the workpiece mark WAM is stopped on the alignment microscope 12. A through hole is formed in the workpiece W at a predetermined pitch for each exposure region, and the transport roller R is rotated by a distance corresponding to the pitch. The workpiece W is held on the workpiece stage 10.

(2) The alignment light illumination means 11 is inserted above the mask M (between the mask M and the light irradiation unit 4) by the alignment light illumination means moving means 11a.

The alignment light illumination means 11 illuminates the alignment light with respect to the mask mark MAM and the focal length pattern FP formed therein. Here, the wavelength of the alignment light is the same wavelength as the exposure light irradiated by the light irradiation unit 4.

(3) The image of the mask mark MAM and the focal length pattern FP illuminated by the alignment light is projected on the glass of the notch or through hole provided in the workpiece stage 10. On the glass plate 10b.

As shown in Fig. 3(a), the alignment microscope receives the projection image of the mask mark MAM and the focal length pattern FP, and the edge of the through hole as the workpiece mark WAM, and the focal length adjustment of the alignment microscope formed on the glass plate. The image of the pattern AP.

(4) The alignment of the mask M and the workpiece W is performed in such a manner that the wheel ring mask mark MAM is set in advance and the positional relationship of the edge of the through hole as the mask mark WAM. At this time, the detection of the mask mark MAM and the mask mark WAM uses a low magnification of the alignment microscope. The control unit 20 performs alignment based on the position information of the mask mark MAM and the workpiece mark WAM.

By the alignment of the mask M and the workpiece W, the annular mask mark MAM and the workpiece mark WAM of the through-hole are formed in a predetermined positional relationship. Thereby, the projection lens focal length pattern FP formed on the inner side of the annular mask mark MAM and the alignment microscope focal length pattern AP formed on the glass plate of the workpiece stage are arranged side by side in the field of view of the alignment microscope. . Thereby, the following focus adjustment operation can be performed.

(5) The focal length adjustment of the projection lens 5 and the focal length adjustment of the alignment microscope 12 are performed in the following order. Here, at this time, the detection of the focal length pattern FP and the AP uses a high magnification of the alignment microscope.

Fig. 4 (a) to (d) are explanatory views for explaining the operation of the mask and the workpiece during the focus adjustment, and the focus adjustment sequence of the present embodiment will be described using Fig. 4 .

(a) As shown in Figure 4(a), the alignment microscope 12 is connected simultaneously. The projection lens focal length adjustment pattern FP projected on the glass plate 10b and the image of the alignment microscope focal length adjustment pattern AP formed on the glass plate 10b. The image signal system is transmitted to the control unit 20.

The control unit 20 performs image processing on the received focal length pattern FP for the projection lens and the image of the focal length pattern AP for the alignment microscope.

Here, the mask stage 13 and the workpiece stage 10 are tied to the origin position. The origin position is the position of the focal length (design value) of the projection lens 5 as described above.

(b) Perform focus adjustment of the alignment microscope. That is, as shown in FIG. 4(b), the control unit 20 moves the workpiece stage 10 in the vertical direction (the optical axis direction ‧Z direction) so as to be in focus with the pattern AP. When focusing on the pattern AP, the control unit 20 stops the movement of the workpiece stage 10 and memorizes the moving distance A from the origin position.

(c) As shown in FIG. 4(c), the control unit 20 moves the mask stage 13 in the vertical direction (the optical axis direction ‧Z direction) so as to be in focus with the pattern FP. When the focal length of the pattern FP is matched, the control unit 20 stops the movement of the mask stage 13 and memorizes the moving distance B from the origin position. The moving distance B of the mask stage must be greater than the moving distance A of the workpiece stage 10.

The focal length adjustment of the alignment microscope 12 and the focal length adjustment of the projection lens 5 may be performed in reverse order, or may be performed simultaneously.

In this state, the alignment microscope focuses on the glass plate 10b of the workpiece stage 10, and the focal length pattern FP is imaged on the glass of the workpiece stage 10, and is projected while being in focus. The mask stage 13 in this state The distance to the workpiece stage 10 is the distance D between the original paintings of the focal length of the exposure device in the current environment.

Here, the exposure processing can be performed in this state not because the focus is already on. In this state, the distance from the mask M to the projection lens 5 is generally not equal to the distance from the projection lens 5 to the workpiece stage 10. When the distance between the two is not equal, the image will be deformed due to aberrations.

Therefore, in a state where the distance D between the original images is maintained, it is necessary to make the mask so that the distance from the mask M to the projection lens 5 and the distance from the projection lens 5 to the workpiece stage 10 are equal to each other. The stage 13 and the workpiece stage 10 are moved.

(d) Therefore, as shown in Fig. 4(d), the moving distance B of the workpiece stage 10 is subtracted from the moving distance B of the mask stage 13 thus memorized, and the value is divided by two. This value is set to C. Next, the mask stage 13 is moved from the origin position to the position of the distance C in the upward direction, and the workpiece stage 10 is moved downward from the origin position to the position of the distance C. In this manner, the distance from the mask M to the projection lens 5 can be made equal to the distance from the projection lens 5 to the workpiece stage 10 while maintaining the distance D between the original images.

This completes the focal length adjustment of the projection lens and the alignment microscope.

As described above, the alignment of the mask M and the workpiece W and the end of focusing are completed, that is, in this state, the exposure operation is restarted.

A projected image of the focused mask pattern is obtained on the workpiece. In this state, the exposure light emitted by the light irradiation unit 4 is transmitted through the mask M and the projection lens 5 to the workpiece W, and the mask pattern is transferred to the workpiece W.

When the exposure is completed, the strip-shaped workpiece W is held by the transport roller R4 and the pressing roller R4', and is conveyed so that the next exposure region reaches the workpiece stage 10, and exposure is performed.

As described above, the exposed strip-shaped workpiece W is wound around the winding drum 2 via the guide roller R5 and the loose portion A2. At this time, the spacer is taken out by the spacer unwinding roller 2a, and the exposed strip-shaped workpiece W is wound around the winding drum 2 together with the spacer.

In the above embodiment, the case where the workpiece is marked as a through hole formed in the peripheral portion of the strip-shaped workpiece is described, but when the strip-shaped workpiece has light transmittance, the mark may be formed on the workpiece. Instead of punching through holes.

Further, recently, since the alignment accuracy between the mask and the workpiece is improved, there are cases where the alignment mark is formed in two or more places, for example, four places. At this time, the alignment microscope is provided with four sets of alignment marks. Among them, if four alignment microscopes are provided, the amount of tilt of the workpiece stage can also be detected.

1‧‧‧Roll out the drum

2‧‧‧ winding drum

3‧‧‧Exposure Department

4‧‧‧Lighting Department

5‧‧‧Projection lens (lens barrel)

6‧‧‧Working table drive mechanism

10‧‧‧Working table

10a‧‧‧ notch (through hole)

10b‧‧‧glass plate

11‧‧‧Aligned light illumination

12‧‧‧Aligning microscope

12a‧‧10 times the use of imaging components

12b‧‧‧1.5 times the use of imaging components

13‧‧‧Mask stage

14‧‧‧Mask stage moving mechanism

20‧‧‧Control Department

M‧‧‧ mask

W‧‧‧Striped workpiece

MAM‧‧‧ mask mark

WAM‧‧‧ workpiece marking

FP‧‧‧Focus lens adjustment pattern

AP‧‧‧Alignment microscope focus adjustment pattern

Fig. 1 is a view showing the overall configuration of an exposure apparatus for a belt-shaped workpiece according to an embodiment of the present invention.

Fig. 2 is a perspective view showing a portion of the alignment light illumination means, the mask stage, the projection lens, the workpiece stage, and the alignment microscope in the apparatus shown in Fig. 1.

Figure 3 is an enlarged view of the mask mark MAM and the focus adjustment pattern. An enlarged view of the FP projection image, the focal length adjustment pattern AP, and the workpiece mark WAM.

Fig. 4 is an explanatory view for explaining the operation of the mask and the workpiece during the focus adjustment.

Fig. 5 is a view showing an example of the configuration of an exposure apparatus for a strip-shaped workpiece.

Fig. 6 is a perspective view showing a portion showing a mask, a projection lens, and a workpiece stage of the exposure apparatus of Fig. 5.

5‧‧‧Projection lens (lens barrel)

10‧‧‧Working table

10a‧‧‧ notch (through hole)

10b‧‧‧glass plate

11‧‧‧Aligned light illumination

12‧‧‧Aligning microscope

12a‧‧10 times the use of imaging components

12b‧‧‧1.5 times the use of imaging components

13‧‧‧Mask stage

M‧‧‧ mask

MAM‧‧‧ mask mark

FP‧‧‧Focus lens adjustment pattern

AP‧‧‧Alignment microscope focus adjustment pattern

Claims (4)

An exposure apparatus for a strip-shaped workpiece includes: a light irradiation portion that irradiates exposure light; a mask stage that supports a mask in which a pattern and a mask alignment mark are formed; and an elongated shape in which a workpiece alignment mark is formed a workpiece holder having a notch or a through hole formed in a strip-shaped workpiece; a projection lens that projects a pattern formed on the mask on the workpiece; and a light-transmitting member disposed on a through hole or a notch of the workpiece stage; An alignment microscope below the light transmitting member; and a control unit for detecting the mask alignment mark and the workpiece alignment mark by the alignment microscope, wherein the mask is aligned, wherein: A focal length adjustment pattern for a projection lens is formed in the mask, and a focus adjustment pattern for the alignment microscope is formed in the light transmission member, and a mask alignment mark wheel formed on the mask is annularly formed in the mask. The projection lens has a focal length adjustment pattern formed by a pattern of lines and gaps formed inside the ring of the mask alignment mark, and a focal length for the alignment microscope formed in the light transmission member A projection formed on the entire line pattern wheel annular inner mask image of the mark, The control unit detects the focal length adjustment pattern for the projection lens and the focal length adjustment pattern for the alignment microscope by the alignment microscope to perform focus adjustment. The exposure apparatus of the strip-shaped workpiece according to the first aspect of the invention, wherein the alignment microscope includes: a first image receiving unit that detects an image at a low magnification; and a second image receiving unit that receives an image at a high magnification, and is covered. When the cover is aligned with the workpiece, the first image receiving portion detects the alignment mark, and when the focus is adjusted, the second image receiving portion detects the focus adjustment pattern. An exposure apparatus for a strip-shaped workpiece according to claim 1 or 2, wherein the workpiece alignment mark is formed in a through hole of the strip-shaped workpiece. A method for adjusting a focal length in an exposure apparatus for a strip-shaped workpiece, which is characterized in that, in the exposure apparatus of the strip-shaped workpiece according to any one of claims 1 to 3, characterized in that: Aligning with the microscope, receiving the image of the focal length adjustment pattern of the alignment microscope, and moving the workpiece stage in the optical axis direction so that the pattern is focused; receiving the image of the focal length adjustment pattern of the projection lens so that the image is received a pattern in which the pattern is focused, a second step of moving the mask stage in the optical axis direction; and a state in which the distance from the mask stage to the workpiece stage is maintained at the end of the step, with respect to the projection lens The third step of moving the mask stage and the workpiece stage such that the workpiece stage and the mask stage are at equal distances.